What is a common identifier for distinguishing between rats and mice?

To distinguish between rats and mice effectively, the size of feet is a reliable identifier. Generally, rats have larger and thicker feet compared to mice, which have smaller and more delicate feet. This size difference is significant, making it easier to identify the animal based on tracks or physical examination.

While other options may have some relevance, they are not as definitive as foot size. For instance, the color of fur can vary widely among individual animals and species, making it an unreliable characteristic for identification. Length of tails can sometimes vary but might not be as pronounced as foot differences, and the size of eyes also varies without providing a clear distinction between the two rodents. Thus, focusing on the size of feet offers a more consistent method for differentiating between rats and mice.